DeNtal tribuNe | January-March, 2010 trends & applications 23 returned to its original position within three months by means of the indirect anchorage of tooth 23 to a miniscrew using a straight wire appliance. In the case of a bite that exposed tongue in each case between the canine and the first premolar. A Titanol Uprighting Spring (FORESTADENT) was attached to the capstan of the miniscrew, and the screw was set to intrusion. There was even some overcorrection of the positioning of the first molars on both sides after five months’ intrusion, resulting in closure of the frontal bite. Figs. 6a–c: Space closure in the region of the upper laterals. Baseline situation: Teeth 25 and 27 are free of caries (a). Using miniscrews (OrthoEasy), it is possible to provide ‘invisible’ treatment (b). Very few elements are required for mesialisation (c). and bone (Figs. 8a & b), the approach adopted was to provide transverse expansion and extrusion of the anterior teeth. Intermaxillary rubber traction braces connected to miniscrews in the lower jaw were used. If the braces had been connected to the lower anterior teeth, undesirable extrusion of these would have resulted (every action has an equal and opposite reaction). Because of the small root surface, this process would have occurred in a much shorter space of time than in the case of the upper anterior teeth. The opposing bone in the lower jaw prevented this undesirable reactive effect. Intrusion Conclusions It may be necessary for therapists to overcome logistical and emotional barriers before they can begin to employ miniscrews, but it is only when they are used that their versatility becomes apparent. Miniscrews make our routine work that much simpler. They enhance the efficiency and effectiveness of many dental appliances, resulting in an overall improvement in treatment quality. DT Figs. 7a–c: Extrusion of a single tooth. Viable lateral incisor following intrusion due to trauma (a). Miniscrew with indirect anchoring of the canine and straight arch technique, in order to extrude tooth 22 (b). Status after three months (c). Vertical tooth displacement Any displacement of the teeth along the vertical axis can present a cosmetic and/or functional problem. The solution is extrusion or intrusion using skeletal Figs. 8a & b: Extrusion in order to close an open bite caused by tongue thrust, with deterioration of the upper jaw. The aim was to extrude the upper frontals over the miniscrew in the lower jaw (a). Status after twelve months (b). anchorage. This technique is very simple to implement and very cost-effective. Extrusion Extrusion using miniscrews This open bite with extrusion of the tongue (Figs. 9a & b) was treated by means of intrusion of the molars and consequent caudal rotation of the maxilla. Miniscrews were inserted in the first and second quadrants Contact Info Dr. Björn Ludwig Am Bahnhof 54 56841 Traben-Trarbach, Germany Tel.: +49 65 41 81 83 81 Fax: +49 65 41 81 83 94 E-mail: bludwig@ kieferorthopaedie-mosel.de may be used for single teeth (Figs. 7a–c) and for groups of teeth (Figs. 8a & b). Trauma had Figs. 9a & b: Intrusion in order to close a tongue and skeletal open bite. Intrusion of the molars was effected using a Titanol Uprighting Spring (FORESTADENT) (a). Status after six months (b). caused the intrusion of tooth 22 (Figs. 7a–c). The tooth was median or paramedian region can be used to stabilise the anterior teeth. Using the standard vestibular mechanical techniques, the gap can be closed without altering the position of the incisors. En masse or canine retraction (e.g. where the premolars are missing) Miniscrews can also be used as an aid in this form of treatment (Figs. 5a–c). In contrast with the conventional appliances, there is no loss of anchorage but rather a biomechanical benefit in terms of more favourable direction of forces. If the miniscrew and the fitting for the active element (traction spring or elastic chain) are positioned at the same level as the resistance centre of the canines, physical movement of the tooth (or teeth) is possible. Space closure in the molar region (e.g. to avoid the need for prosthetic measures) Premature loss of the primary molars has not yet been eradicated despite all the advances made in prophylactic treatments. There may be a need for appropriate therapy, particularly in cases in which the adjacent teeth are not carious (Fig. 6a–c). What should the patient be offered—implants, bridges or space closure treatment? With a view to the realistic long-term prognosis for the anchorage teeth, conservation of the surviving natural teeth, and the minimisation of the effects on the existing materials, a prosthetic solution would not appear to be appropriate. The basic concept of restorative dentistry—first destroy, in order to reconstruct— is frequently not the best solution. Let us assume that the strategy adopted is to mesialise tooth 27, in order to compensate—using a natural method— for the loss. The skeletal anchorage means that undesirable side effects, such as reciprocal space closure, are avoided. Only a few elements (brackets, springs etc.) are needed to support the mesial movement. The treatment remains invisible to the casual observer, while in comparison with the stated alternatives, it is very costeffective and provides for a high level of conservation of the natural elements. The prognosis for the long-term preservation of the natural teeth is very good.